Linux Diagnostics And Troubleshooting

What you’ll learn
Linux Diagnostics And Troubleshooting
To fix common issues on a Red Hat Enterprise Linux machine, using tools provided by the distribution.
What is troubleshooting?
Troubleshooting a login issue
Troubleshoot a web server issue using the log files
Troubleshoot a FTP Connectivity Issue
System Monitoring with Cockpit
Centralized log server using rsyslog
Advanced Intrusion Detection Environment (AIDE)
System Auditing with auditd
Identify various harwdare and their problems
Hardware Error Reporting using mcelog and rasdaemon
Manging Kernel Modules
Troubleshooting to disable MSI-X interrupt handling in the driver
Troubleshooting Storage Issues
Overview about Filesystems, Device Manager & Device Mapper Multipath
Recovering from File System Corruption
Migrating a Volume Group from one system to another
Configuration of Iscsi target & Initiator
Troubleshooting RPM Issues
Recover a corrupted RPM Database
Working with transaction history using Yum command
Troubleshooting a Network Issues
Scanning Network Ports using nmap
nc & iptraf-ng commands
Troubleshooting a network issue (One network interface is not working properly)
Troubleshooting a Boot Issues
Lab on Basic System Recovery
Reset the root passwd using installation disk or rd break
Troubleshooting a Security Issues
Troubleshooting a SELinux Issue
SELinux Audit Logs & Troubleshooting
Overview of PAM Security & Concepts of PAM
Various practice lab session

Requirements
PC or Laptop with internet Connection
A RHCSA/RHCE certification, or equivalent knowledge is required to successfully sit this course.
Description
Course Description

Linux Diagnostics And Troubleshooting

Introduction

What is troubleshooting?

Troubleshooting a login issue

Collecting Information

System Journal

Troubleshoot a web server issue using the log files

Using Red Hat Resources

Collecting Information with SOSREPORT

Practice Lab Session

Troubleshoot a FTP Connectivity Issue

Monitoring Systems

System Monitoring with Cockpit

Performance Co-Pilot or pcp

Centralized log server using rsyslog

Practice Lab Session

Intrusion detection software to monitor changes

Advanced Intrusion Detection Environment (AIDE)

Practice Lab Session

System Auditing with auditd

Identifying Hardware Issues

Identify various harwdare and their problems

Hardware Error Reporting using mcelog and rasdaemon

Memory Testing using memtest86+ package

Manging Kernel Modules

Loading and unloading modules

Managing module options

Troubleshooting to disable MSI-X interrupt handling in the driver

Troubleshooting Storage Issues

Overview of Linux Storage Stack

Virtual File System

Filesystems & Device Manager

Device Mapper Multipath

Recovering from File System Corruption

Checking & Repairing ext3/ext4 fs using e2fsck

Checking & Repairing xfs fs using xfs_repair

Recovering LVM Issues

Practice Lab Session – using vgcfgrestore

Migrating a Volume Group from one system to another

Recovering Metadata in LVM

Practice Lab Session

Configuration of Iscsi target & Initiator

Practice Lab Session on iscsi target & initiator – 1

Practice Lab Session on iscsi target & initiator – 2

Troubleshooting RPM Issues

Resolve package management dependency issues

Identify & fix dependency issue

Recover a corrupted RPM Database

Working with transaction history using Yum command

Reverting & repeating transaction using yum command

Practice Lab Session

Troubleshooting a Network Issues

Check Network Connectivity

Scanning Network Ports using nmap

Communicating with a remote service using nc command

Monitoring Network traffic using iptraf-ng

Troubleshooting a network issue (One network interface is not working properly)

Troubleshooting tips related with device names of ethernet interface

Disable consistent network device naming

Overview NetworkManager

Practice Lab Session

Capturing Packets with tcpdump

Practice Lab Sessions

Troubleshooting a Boot Issues

Linux Boot process

Booting of RHEL 7 with systemd

Overview of Grub2

Grub2 features

Booting into Grub Menu

Protect Grub by appying a password

Lab on Basic System Recovery (Initramfs file missing/Corrupted)

Lab on Basic System Recovery (Grub related issues like grub is missing)

Lab on Basic System Recovery (Master Boot Record missing/corrupted)

Rescue Modue in RHEL 7

Practice Lab Session

Reset the root passwd using installation disk

Reset the root passwd using rd.break

Repairing File System Issues at boot

Fix issues at /etc/fstab at boot – Lab Session

Troubleshooting a Security Issues

Troubleshooting a SELinux Issue

Changing SELinux context

troubleshooting ftp connectivity issue using booleans

SELinux Audit Logs & Troubleshooting

Overview of PAM Security

Concepts of PAM

PAM Modules & Configurations

PAM Module Groups

Control Flags in PAM

PAM Modules

last lecture

Who this course is for
Linux Diagnostics and Troubleshooting course is aimed at senior system administrators who wish to learn more about troubleshooting.